Cover attaching assembly



United states 3,944,105 Patented July 17, 162

3,044,106 COVER ATTAtIl-HWG ASSEMBLY Robert A. Papsdorf, Claremont,Califi, assignor to Emerson-Pryne Company, Pomona, Caiif., a corporationof Delaware Filed Apr. 19, 1960, Ser. No. 23,171 11 Claims. (Cl. 16-479)This invention relates to means for removably attaching a cover to ahousing, and more particularly to a means which is movable between afirst position in which the cover closes the housing and a secondposition in which the cover is spaced from the housing.

A typical application of such closure means is found in a sheet metalhousing for enclosing a fan or electric light recessed into the wall orceiling of a room. As a rule such housings have an open side which isclosed by a cover consisting of a perforated grill, in the case of afan, or a frame holding a glass lens, in the case of a light.

With equipment of this character, it is important to have easy access tothe interior of the housing for service and replacement of parts. Anelectric light burns out aft-er a time and needs replacing. Aventilating fan needs periodic oiling or cleaning. These requirementsfor periodic and sometimes frequent access to the interior of thehousing make it desirable that the cover be easily removable, preferablywithout the use of any tools at all. Yet the cover must be held firmlyin place in order to perform its primary function.

In the case of lighting and ventilating equipment which is oftenrecessed into the ceiling of a room, the person servicing the equipmentmust stand on a ladder and hold a fresh bulb or oil can in one handwhile steadying himself with the other hand. Under these conditions itis obviously desirable that the cover be easily removable, withouttools, by a simple hand movement. Also, to avoid burdening the workmanwith an extra item to hold and to eliminate danger of cover breakage, itis desirable that the cover be securely held by the attachment meanseven after it has been moved from its closed position to an openposition which permits access to the interior of the housing. inaddition, it is desirable that the attachment means should firmly, holdthe cover in either the open or closed position, but yet be easilymovable from one to the other.

Accordingly, one general object of this invention is to provide novelattachment means for removably attaching a cover to a housing in whichthe attachment means is movable between a first position in which thecover closes the housing and a second position in which the cover isspaced from the housing.

A second object of this invention is to provide attachment means of thischaracter wherein the cover is firmly held in either of its twopositions, but is easily movable from one position to the other by asimple hand movement.

Another object of this invention is to provide a closure means of theabove-noted character which is simple and sturdy in structure,inexpensive in manufacture, and reliable in operation.

An additional object of this invention is to provide a novel mechanicallinkage which is formed from simple stamped parts and which provides asmooth movement without fixed pivots or bearings.

To embody all of these desirable features in a simple, sturdy, andinexpensive structure there has been devised a novel mechanicalarrangement which contains a flat arm pivoted at one end to the coverand having an abutment formed on one surface thereof. A socket isstamped into the housing with openings cut therein to receive the arm,and spring means holds the arm engaged in the socket with the abutmentbearing against one edge of the socket.

Although the arm is not attached to the socket in any way, it is firmlyheld in place by the top of the socket and the spring means, and it canbe moved through an are by a free pivoting movement. I

One edge of the offset piece of the housing forming the socket engagesthe abutment and is shapedto form a cam surface which interacts with theabutment, and the spring means, to develop a force holding the arm ineither of two stable positions: one position corresponding to the closedposition of the cover, and the other corresponding to the open positionof the cover.

Both the arm and the socket in the housing can be very inexpensivelyformed by simple operations on a punch press, and the linkage can bevery quickly assembled by simply sliding the arm into the socket andattaching the spring means to the arm and to the housing. It can be justas quickly disassembled by removing the spring means and sliding the'armout of the socket.

In a preferred embodiment of the invention two such linkages areemployed, one on each of two opposing sides of the housing. In thisembodiment the housing is made in two sections which fit together inoverlapping relation at the two sides carrying the linkages, and thesockets for the linkages are stamped into the inner section in the areaof overlap, such that the opening left by the socket is covered andsealed by the overlapping section. The covering of the socket area by anoverlapping section is a valuable feature of this invention, because ifthesockets were not covered they might become filled with plaster whenthe wall or ceiling around the housing is finished, and the arms wouldnot swing freely as required for proper operation.

Another very important feature of this invention is arrangement wherebya smooth swinging movement in either of two directions is accomplishedwithout a pivot pin or the like making a fixed connection. \To achievethis, the arm is allowed to project through the back of the socketthrough an opening whose length is approximately equal to the width ofthe arm divided'by the cosine of the are through which the arm ismovable. When the arm is moved in one direction it pivots freely againstthe socket at one end of this opening, and its movement in thatdirection is limited by abutment of the arm against the other end of theopening. When the arm is moved in the other direction it pivots freelyagainst the other end of the opening, but since the arm is in contactwith both ends of the opening at the end of its travel, the transfer ofthe pivot point from one end of the opening to the other is achievedvery smoothly.

The spring means comprises an expansion spring stretched between twohooks, one lanced into the arm and the other lanced into the housingnear the socket. These hooks can be formed inexpensively by the sametype of operation which forms the socket and the abutment.

How the above and other objects and advantages of this invention havebeen achieved will be apparent to those skilled in the art from thefollowing description of one illustrative embodiment thereof, inconnection with the annexed drawings, in which:

FIG. 1 is a median section of a preferred embodiment of the inventionshowing the attachment means and cover in closed position.

FIG. 2 is a fragmentary section of the housing on line 22 in FIG. 1.

FIG. 3 is a fragmentary section-of the housing wall on line 3-3 in Fig.l.

FIG. 4 is a partial section and elevation at reduced scale showing'thecover and attachment means in open position.

FIG. 5 is a horizontal section taken on the line 55 of FIG. 4.

FIG. 6' is a fragmentary plan view of one corner of the housing made intwo overlapping sections, with the socket on the housing formed in thearea of overlap.

Referring now to FIG. 1 there is shown a housing 10 recessed into aceiling 12 for the purpose of holding a The housing '16 serves as aplaster frame to define anopening in wall 12 into whicha fan, lightfixture, or the like is recessed. As

. may be seen from FIG. 5, the housing is normally rectangular inoutline, though I am not necessarily limited to any exact shape. Thehousing is open at the top side between the inwardly turned flanges 10aand 1%. This opening may be closed by any suitable member; but asillustrative of such closure members there is here shown in FIG. 4 aportion of a reflector 13 for a light fixture. For additional details ofthe construction of this memher and its functions, reference may be hadto my copending application filed March 14, 1960, Serial No. 14,880 forRecessed Lighting Fixture having a Separable Pre-Wired Section.

The lower face of the housing-which is also open, is

Q I normally closed by a cover assembly comprising a frame 14 thatsupports a perforated grill, or glass lens 16. An angle bracket 18attached to the side of frame 14 is provided to receive the arm 2b of anattachment assembly.

It will be understood that two attachment assemblies are commonlyemployed for housings of this character,

- and that an identical assembly, not shown, is attached as indicated inFIG. 5 to the side of the housing opposing the side viewed in FIGS. 1, 2and 3.

The attachment assembly comprises an arm 20 which is arcuately movablein a socket 24 formed in housing 10.

The lower end of arm 20 is bent to pivotallyengage an opening 19 cutinto bracket 18 to support the cover assembly. In the closed position(FIG. 1) arm 20 is spring loaded upwardly and holds frame 14 firmlyagainst ceiling 12. But arm 24) can be swung downwardly against theforce of the spring to lower the cover assembly to a spaced, or openposition as shown in FIG. 2. When moved to the open position, thedirection of spring load-j 'ing on 'arm 2% shifts and it becomes springloaded in a direction to hold the conveyor assembly in the open positionas shown in FIG. 2. .In the open position, frame 14 can be pivoted aboutthe ends of arms 20 to the position 14a as indicated by the dotted linesin FIG. 4, for convenient access to the interior of the housing forservice or replacement'of the apparatus within the housing.

' When the cover assembly is moved from the open position (FIG. 4)toward the closed position (FIG. 1) the spring loading on arm 20 shiftsback again, and arm 20 an upward or counterclockwise moment on arm 29.When abutment 22' is on the lower straight section as shown in FIG. 4,spring 26develops a downward or clockwise moment on arm 20. Theswitchover in the direction of the moment occurs when spring 26 isparallel with the axis of arm 29, i.e. when abutment 22 is aligned withthe center of the rounded sectionof the cam surface.

It will be noted in FIG. 1 that in the closed position of the cover,abutment 22 is only slightly past the apex of the V, while in the openposition it is extended almost to the end of the cam surface. There is athree-fold reason for this arrangement. First, it is desirable that thecover assembly be pressed firmly against ceiling 12. Therefore theupward movement on arm. 20 is so directed by the position of arm 20 thatit will securely hold frame 14 against the ceiling. It will beunderstood that this is accomplished by having abutment 22 close to theapex of the 'V in the closed position, since the upward moment increasesin proportion with the distance of abutment 22 from the point of the V.Secondly, it is desirable to have arm 20 completely retracted insidehousing 16 when the cover assembly is detached for shipping, andthis'requires that arm 20 be spring loaded to move upwardly beyondtheclosed position of the cover assembly,

the cover that arm 20 be spring loaded downwardly during a largeproportion of the final downward swing of arm 28. This is accomplishedby locating the abutment close to the apex of the V of cam surface 2.8in the closed 1 position of the cover.

In addition to providinga moment on arm 20, as described above, spring26 serves a second important function in holding arm 29 engaged insocket 24.

Referring especially to FIGS. 1, 2 and 3, it will be seen that socket 24is formed by cutting the side wall of the housing along the line of camsurface 28 and then offsetting inwardly the wall at one side of the cut.Thus one cut edge is spaced inwardly of the other out edge and becomescam surface 28. Another cut is made at the opposite side of socket 24and here also one cut edge 29 is oifset inwardly by pressing on'the areaof socket 24.

' Thus there are two slots 28s and 29s formed in the side becomes springloaded to hold frame 14 against ceiling 12. j

This change in the spring loadingof arm 20 is achieved by theinteraction of an abutment 22 on arm 20, a cam surface 28 on housing 10,and spring means26 pressing abutment 22 against cam surface 28.

Cam surface 28 is shaped like a broad, round-bottomed V. Cam surface 28has two substantially straight sections connected by an intermediaterounded section. The angle between the straight sections is here shownas about 90 but it may be increased ordecreased asdesired to suitconditions. As a possible variation, theentire surface 28 may be curvedbut having a changing radius to approximate the shape illustrated."Abutment 22 bears against one straight side section when the cover is inthe closed position and against the other side section when the cover isin the open position.- When the cover is moved from one position to theother, abutment 22 moves arm 20 when the abutment 22 is displaced ineither direction from the intermediate section of the cam surface.

When abutment 2 2 is on the upper straight section of the cam surface,as shown in FIG. 1, spring 26 develops wall.

Referring to FIG. 3, socket 24 will be seen to be spaced from the; innerface of the housing by a distance slightly greater than the thickness ofarm 20. Two openings 28; and 29s are formed at opposing sides of thesocket mound, one below the cam surface 28, and the other generallyopposite the apex of the V on surface 28. Arm 20 is slid under thesocket 24 and through the two openings 28s and '29s to bring abutment 22against cam surface 28, where it is held, by spring 26. Spring 26extends between a hook 363 on the housing and a hook 32 on the arm.

Since the space between the socket wall 24 and the inner surface ofhousing 10 is approximately equal to the thickness of arm 21 the arm isrestrained from movement in all planes except one parallel to the planeof the wall against which it rests. However, it can be swung in eitherdirection by pivoting against the socket at either end of opening 29s.When moved downwardly, the lower edge of the arm pivots against thelower end of opening 29s and when moved upwardly the'upper edge of thearm pivots against the upper end of opening 29s.

' When arm 20 is raised to the position of FIG. 1, spring 26 liesagainst the upper side of socket 24. As the arm swings down to thelowered position of FIG. 4, the spring rides up onto the surface ofsocket24 which is ofiset inwardly from the plane of the surroundingmetal plate. This causes spring 26 to bow, as seen in FIG. 2 wherein thespringis shown in a position between FIGS. 1 and 4. Also spring 26 isslightly elongated. These eifects combine to resist movement of the armdownward from the position of FIG. 1 and insure that the front 14 isheld securely in place when fully raised.

An important feature of this invention is the arrangement whereby thetransfer of pivot points from the downward to the upward movement ismade smoothly. The length of opening 29s is approximately equal to thewidth of the arm divided by the cosine of the are through which the armis movable. Therefore, when the arm approaches its lower limitingposition, as shown in FIG. 3, the side of the arm opposing the pivotpoint comes into contact with the other end of opening 29s. Thus at theextremes of arcuate travel the sides of arm 20 are in contact with bothends of opening 2%, such that the transfer of pivot point from one endof opening 29s to the other is made smoothly. In this arrangement it ispreferable that the downward movement of the arm be limited by abutmentof arm 29 against the ends of opening 29s, to insure absolutely smoothtransfer of the pivot point, but this is not essential to the invention.

In the preferred embodiment of the invention'described, socket 124 andhook 32 are formed in the sheet metal wall by lancing, an operation inwhich sheet metal is simultaneously cut and punched. In this embodiment,openings 28s and 29s are formed by shear cuts made during the lancingoperation, and widened to the appropriate width when the materialbetween the cuts is punched to form the mound. The boundaries of thehook are also defined by lanced cuts. A similar operation may be used toform abutment 22 in arm 20.

In FIG. 5 is shown a sectional view of the entire housing illustratingtwo sockets 24 which are located on opposing sides of the housing. Thehousing is preferably but not necessarily made of two overlappingsections 38 and 49. Both sections are stamped from a flat blank of sheetmetal and are then bent into a U-shape, one section having longer armsthan the other. One section 38 forms three full sides of the rectangularframe and the other section 44 forms the fourth side. This lattersection has a tab 48a at each end bent at 90 to the intervening side ofthe frame and thus overlapping end portions of the two opposite sides ofthe housing formed by section 33. The tabs are preferably joined to theother section by spot welding at 41 but other suitable means may beemployed. The sockets 24 are each lanced in one of the tabs 46a. Sincethe tabs are inside the finished housing, the section 33 lies over orcovers the outer surface of the tabs 40a on section 4i) and the area ofoverlap is such that the openings formed by the sockets are outwardlysealed by the overlapping portions of housing section 38. Thisarrangement is very important in housings which are to be recessed intoceilings, since the cover afforded by the overlapping section preventsplaster from entering the sockets, which are usually located near. theplaster level. Since housings of this character are generally made intwo sections for practical reasons, this protection is gained at noextra cost in material or time.

From the foregoing description it will be apparent that this inventionprovides a novel cover attachment means which is simple and sturdy instructure, inexpensive to manufacture, and reliable in operation. Itshould be understood that this invention is not limited to the specificstructures disclosed herein, since many modifications can be made in thestructure without departing from the basic teaching and scope of thisinvention.

I claim:

1. Means for attaching to a housing or the like a cover closing anopening in the housing, comprising:

an arm pivotally connected near one end to the cover;

arm mounting means on the housing slidably receiving the other end ofthe arm, the arm being free to move both longitudinally and swinginglybetween a first position in which the cover closes the opening and asecond position in which the cover is spaced from the opening;

a cam follower on the arm engaging a cam on the mounting means, said camhaving two cam surfaces disposed at an angle to each other and connectedby an arcuate junction; 7 4 I and spring means acting to press the camfollower against the cam, the spring means being adapted to produce acomponent of force acting to move the cam follower along one of said camsurfaces and away from said junction when the cam follower is displacedin either direction from said junction.

2. Means for attaching to a housing or the like a cover closing anopening in the housing, comprising:

an arm pivotally connected at one end to the cover;

arm mounting means on the housing slidably receiving the other end ofthe arm, the arm being movable 'both longitudinally and through an arerelative to the housing between a first position in which the covercloses the opening and a second position in which the cover is spacedfrom the opening;

a cam follower on the arm engaging a cam surface on the mounting means,said cam surface having two substantially straight sections connected bya rounded section;

spring means acting to press the cam follower against the cam surface,the cam follower bearing against one of the straight sections when thearm is in its first position, and bearing against the other of thestraight sections when the arm is in its second position, and beingmovable over the rounded section when the arm is moved from one positionto the other; V v

the spring means being connected to the housing and to the arm atpositions located to develop a force parallel with the axis of the armwhen the cam follower is positioned centrally of the rounded section andto develop a force at" an angle to the axis of the arm when the camfollower is displaced in either direction from the rounded section, andthe force developed by the spring means having a component directedalong a straight section whenever the cam follower is displaced ineither direction.

3. Means for attaching to a housing or the like a cover.

closing an opening in the housing, comprising:

a relatively long flat arm pivoted at one end to the cover and having anabutment protruding from one surface thereof near the other end thereof;

a relatively flat base plate attached to the housing, the plate having adepression punched into one surface thereof to form a raised socketprotruding from the other surface thereof, the height of the socketbeing greater than the thickness of the base plate plus the thickness ofthe arm;

first and second openings formed in the plate at opposing sides of thesocket, each opening being slightly wider than the thickness of the armand longer than the Width of the arm;

the arm being positioned between the socket and said other surface ofthe base plate, said abutment bearing against the edge of the socketabove the first opening therein, and said other end of the arm extendingbeyond the socket through the second opening therein;

the arm being movable parallel with the surface of the plate; and springmeans acting to press said abutment against the edge of the socket atthe first opening therein.

4. The combination defined in claim 3 wherein the periphery of thesocket at the first opening therein has two substantial branchesdisposed at an angle to each other and connected by an intermediaterounded section;

, 5. The combination defined. in claim 3 wherein the arm is movabletoward "a first extreme position by pivotal contact with the side wallof the socket ata first end of the second opening therein, and movabletoward a second extreme position by pivotal contact with the side wallof the socket at the second end of the second opening therein. i 6. Thecombination defined in claim 5 wherein said first position of the arm isdefined by abutment of'the'arm against the side wall of the socket atthe second end of the second opening therein;

and wherein said second position of the arm is defined by abutment ofthe arm against the side wall of the socket at the first end of thesecond opening therein. 7. The combination as defined in claim 3 whereinthe housing is made of twosections attached together in overlappingrelation, and wherein said socket is formed'on we the inner one of saidtwo sections within the area of overlap such that the depression underthe socket is covered by the overlapping portion of the other section.

8. A mechanical linkage for linking together two members, one of whichis movable relative to the other, comprising: r r

a relatively long flat arm adapted atone end'to. be attached to onemember and having a raised abut ment protruding from one surface thereofnear the other end thereof; 1

a relatively fiat base plate attached to the other member, the baseplate having afiat area punched from one side of the plate-to form araised area protruding from the other surface of the plate;

'a first and a second opening formed in the plate at T opposing sides ofthe raised area, each opening being wider than the thickness of the armand longer than the width of the arm;

I the arm being positioned between the raisedarea and said other surfaceof the base plate with said abutment bearing against a cut edge of theraised area along the first opening, and said one end of the armextending through the second opening; spring means acting to press saidabutment against the cut edge of the raised area along the firstopening; and the arm being movable parallel with the surface of the baseplate by swinging movement about a pivot substantially at the secondopening in the base plate. j 9. The combination defined in claim 8wherein the arm 5 is movable in one direction by pivotal contact withthe side wall of the raised area at one end of the second opening, andmovable in the other direction by pivotal contact with the side wall ofthe raised area at the other end of the second opening therein, andwherein the length of the second opening is approximately equal to thewidth of the arm divided by the cosine of the are through which the armis movable.

10. Means for attaching to a housing or the like a cover closing anopening in the housing, comprising:

sitions on a wall of the housing;

an arm pivotally connected at one end to the cover, and slidably andswingingly received at the other end between said plates to swingthrough an arc relative to the housing between 'a first position inwhich the cover closes the opening and a second position in which thecover is spaced from the opening;

a fixed cam on one of said plates and a cam follower on said arm at aposition between the ends of the arm actuating the arm to move itlongitudinally relative to said plates and the housing as the arm movesbetween said first and second positions;

and spring means connected'between. a fixed anchor and the arm andacting to press the cam follower against the cam said spring. meansbeing the sole means resisting slidable withdrawal of the arm frombetween said plates. i V

11. Means for attaching to a housing or the like a cover as'in claim 10,in which one of the plates provides stop means spaced apart a distancegreater than the width of the arm and engageable with opposite edges ofthe arm near said other end to provide fixed points about which the armpivots in moving'from one position to the other.

References Cited in the file of this patent UNITED STATES PATENTS PryneMay 19, 1953 Beber et al. Dec. 27, 1955 a pair of parallel, spacedplates mounted in fixed po-

